On the Base of a large Lacertian Cranium from the Potton Sands, presumably Dinosaurian

Abstract

The specimen on which this note is based was found by Mr. Charlesworth in the Potton Sands, near Potton, in Bedfordshire. The bed of phosphatic nodules which there occurs in the brown sands, named by Conybeare and Fitton Woburn sands, is probably of the age of the Purbeck-Wealden formation, though there is also a possibility that it may be as new as the upper part of the Lower Greensand. The formation has yielded, besides numerous Ichthyosaurs, Plesiosaurs, and Pliosaurs, with which the fossil has nothing in common, some Teleosaurs and several Dinosaurians. The only Dinosaurian genus, however, of which the remains are numerous and varied is Iguanodon , represented chiefly by vertebræ, teeth, fragments of jaws, and phalanges. All the vertebrate remains appear to have been sifted on that pebbly shore; and the larger bones were probably deposited on a different horizon. The only other Dinosaurian genus indicated by teeth would seem to be Megalosaurus ; hence, on ordinary principles of association, we might suspect that any new bone inferentially Dinosaurian probably pertained to one or other of these types.